1. Field of the Invention
The present invention relates to tele-diaphanography apparatus, that is to say apparatus suitable for examining human or animal tissues by transillumination thereof for the primary purpose of locating tumors, whether malignant or benign.
2. Description of the Related Art
The detection of tumors at an early stage of their development is particularly desirable as it frequently enables the tumors to be removed from the patient so as to prevent the tumorous condition from spreading to other parts of the body. This is particularly true of cancerous tumors of the female breast.
Breast-screening of women to detect cancerous tumors is now commonplace, but current diagnostic methods and apparatus all have disadvantages. The most common diagnostic methods are palpation and X-ray mammography. Palpation is a relatively subjective method and is therefore somewhat unrealiable, while X-ray mammography, though very reliable, carries a slight risk of inducing cancer owing to the X-ray irradiation used in the examination. A further diagnostic method in which renewed interest has been shown recently is diaphanography. This method relies on transilluminating the brest tissue using visible or infra-red light and recording the resultant image. Such transillumination techniques have the attraction that the non-ionising radiation which passes through the brest tissues carries no risk of inducing brest cancer. A method and apparatus utilising such a system is described in my co-pending British Patent Application No. 2092856A.
When using the diagnostic method and apparatus of British Patent Application No. 2092856A it is usual as a first stage of the examination to perform a visual examination of the brest by placing the light source housing beneath the breast and inspecting the superior surface of the breast to detect the presence of any shadows (indicative of neoplasms) and areas of increased brightness (indicative of cysts). Thereafter, as a second stage in the examination, a record of the transilluminated image is made, for example by using an infra-red television camera to produce a color coded image which can be stored on video-tape or by photograping the image displayed on a visual display unit.
However, we have found that in performing such a visual examination the housing surrounding the light source which is placed beneath the breast can get very hot and subsequent application of the hot housing to a patient when producing a permanent record of the transilluminated image can cause the patient considerable discomfort. The present invention aims to overcome this disadvantage.